A wick-based diffuser is configured for diffusing a liquid volatile substance composition into an air flow path extending through the diffuser to disseminate the volatile substance composition throughout a surrounding volume (e.g., a vehicle interior). Diffusers may comprise a body defining a hollow interior and having an air flow path extending therethough； a reservoir； a wick extending from the reservoir and into the hollow interior of the body； and a closure mechanism configured to selectably isolate the wick and the reservoir from the air flow path extending through the body. Wick-based diffusers may be mounted to a support device via a low-friction mounting mechanism located above a center of gravity of the diffuser, such that the diffuser self-aligns in an upright orientation under the influence of gravity.
